Thin film transistor liquid crystal display (TFT LCD) devices are one of main types of flat panel display devices at the present time, and have become an important display platform for modern IT and video products.
The main driving principle of a TFT LCD device is as follows. The main board of the system connects R/G/B compressed signals, control signals, and power to a connector on a printed circuit board (PCB) via wires. After being processed by a timing controller (TCON) chip on the printed circuit board, data is connected to the display area on the display panel via the printed circuit board, a source-chip on film (S-COF) circuit and a gate-chip on film (G-COF) circuit, so that the liquid crystal display device obtains required power supply and signals. This is shown in FIG. 1.
In order to achieve turn-on of the gate, it is required to provide a gate-on voltage VGH for the gate-chip on film circuit. However, in the prior art, the gate-on voltage VGH is unchangeable after its design is completed. If the gate-on voltage VGH needs to be changed in a subsequent process, it has to be achieved by providing an external voltage or changing the design scheme.
Thus, there is an urgent need to provide a solution for changing the numerical value of the gate-on voltage in order to solve the above problem.